Setback for Ebola Vaccine

Officials at a Swiss hospital today announced they are temporarily halting trials of VSV-ZEBOV, the Ebola vaccine from Merck and NewLink. The trial is being conducted at Hopitaux Universitaires de Geneve. It will resume on Jan. 5, 2015.

The decision was made after 4 volunteers developed mild joint pain in their hands and feet from 10 to 15 days after being vaccinated. There are 59 volunteers participating in the trial at the Swiss site.

“These symptoms were not part of the expected side effects and were not included in the prior information given to volunteers,” the officials said in a statement announcing the decision. When the trial resumes, the vaccinations will be given to a maximum 15 volunteers per week “in order to ensure optimal monitoring conditions.”

The onset of joint pain after vaccination is very common, the officials said. “This happens, for instance in 1 out of 5 vaccinations against rubella,” and the phenomenon “does not worry specialists.”

Halting the trial was necessary “to ensure that the symptoms which have been identified are benign and transient.”

Similar trials are being conducted in the US, Canada, Germany, and Gabon. So far there have been no similar symptoms reported in those trials.

A spokeswoman for Merck said the action was "a precautionary measure, following the occurence of transient complaints of joint pain in a small number of study volunteers receiving higher dose levels of the vaccine."

As a result of the complaints, when the trial resumes participants will get lower doses, she said.

"Results from ongoing and planned Phase I studies will help define the apprpriate dose and overall safety and tolerability profile" of the experimental vaccine, she said.

on Dec 2 i

Before the setback the hospitalssued a glowing report about the progress of the trial, noting that “the vaccine is well tolerated by volunteers.” More than 350 people volunteered to participate in the Swiss trial, according to the report.

At that time the hospital said it had started r

ecruiting volunteers who intend to travel to West Africa to offer them the vaccine as protection against infection. “Those volunteers will not receive a placebo for ethical reasons, “ the hospital said.

The Merck/NewLink vaccine is one of three drug candidates whose manufacturers and others involved in clinical trials have been granted US legal immunity from any claims arising from negative consequences of vaccination. US Health and Human Services Secretary Sylvia Burwell on Dec. 9 granted that protection under the Public Readiness and Emergency Preparedness Act. The immunity applies only to claims in the US.